Assertion : A 30% solution of `H_(2)O_(2)` is marketed as '100 volume' hydrogen perocide.
Reason : 1 L of 30 % `H_(2)O_(2)` will give 100 mL of oxygen at STP.

Options

A. If both assertion and reason are true and reason is the correct explanation of assertion.
B. If both assertion and reason are true but reason is not the correct explanation of assertion.
C. If assertion is true but reason is false.
D. If both assertion and reason are false.

Explanation

To solve the question, we need to analyze both the assertion and the reason provided.

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that a 30% solution of H₂O₂ is marketed as '100 volume' hydrogen peroxide.
- This means that the concentration of hydrogen peroxide in the solution is significant enough to produce a certain volume of oxygen gas when it decomposes.

2. **Understanding the 30% Solution**:
- A 30% solution of H₂O₂ means that there are 30 grams of H₂O₂ in every 100 mL of solution.
- For 1 liter (1000 mL) of this solution, the total amount of H₂O₂ is:
\[ \text{Amount of H₂O₂ in 1 L} = 30 \, \text{g} \times 10 = 300 \, \text{g} \]

3. **Chemical Reaction**:
- The decomposition of hydrogen peroxide can be represented by the equation:
\[ 2 \, \text{H₂O₂} \rightarrow 2 \, \text{H₂O} + \text{O₂} \]
- From this balanced equation, we can see that 2 moles of H₂O₂ produce 1 mole of O₂.

4. **Calculating Moles of H₂O₂**:
- The molar mass of H₂O₂ is 34 g/mol. Therefore, the number of moles in 300 g of H₂O₂ is:
\[ \text{Moles of H₂O₂} = \frac{300 \, \text{g}}{34 \, \text{g/mol}} \approx 8.82 \, \text{mol} \]

5. **Calculating Volume of O₂ Produced**:
- According to the reaction, 2 moles of H₂O₂ produce 1 mole of O₂. Therefore, the moles of O₂ produced from 8.82 moles of H₂O₂ will be:
\[ \text{Moles of O₂} = \frac{8.82}{2} \approx 4.41 \, \text{mol} \]
- At STP (Standard Temperature and Pressure), 1 mole of gas occupies 22.4 L. Thus, the volume of O₂ produced is:
\[ \text{Volume of O₂} = 4.41 \, \text{mol} \times 22.4 \, \text{L/mol} \approx 98.8 \, \text{L} \]
- This can be approximated to 100 L.

6. **Conclusion**:
- The assertion is true because a 30% solution of H₂O₂ does indeed correspond to '100 volume' hydrogen peroxide.
- The reason, however, states that 1 L of 30% H₂O₂ will give 100 mL of oxygen, which is incorrect since it actually produces approximately 100 L of oxygen.

### Final Answer:
- Assertion: True
- Reason: False